Treatment of Bio-Treated Coking Wastewater by Catalytic Ozonation with Semi-Batch and Continuous Flow Reactors
| Autor: | Jianbing Wang, Heng Xu, Weiyi Wang, Can He, Xieyang Xu, Xiangyu Ji |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
catalytic ozonation
lcsh:Hydraulic engineering Ozone Geography Planning and Development Kinetics 02 engineering and technology 010501 environmental sciences Aquatic Science rate constant 01 natural sciences Biochemistry reactor Catalysis Reaction rate chemistry.chemical_compound lcsh:Water supply for domestic and industrial purposes Reaction rate constant lcsh:TC1-978 Mass transfer coking wastewater polynuclear aromatic hydrocarbons 0105 earth and related environmental sciences Water Science and Technology lcsh:TD201-500 Chemical oxygen demand 021001 nanoscience & nanotechnology Pulp and paper industry chemistry Sewage treatment 0210 nano-technology |
| Zdroj: | Water Volume 12 Issue 9 Water, Vol 12, Iss 2532, p 2532 (2020) |
| ISSN: | 2073-4441 |
| DOI: | 10.3390/w12092532 |
| Popis: | In this work, the treatment of bio-treated coking wastewater (BCW) by catalytic ozonation was conducted in semi-batch and continuous flow reactors. The kinetics of chemical oxygen demand (COD) removal were analyzed using BCWs from five coking plants. An integral reactor with catalytic ozonation stacked by ozone absorption (IR) was developed, and its efficiency was studied. The catalyst of MnxCe1-xO2/&gamma Al2O3 was efficient in the catalytic ozonation process for the treatment of various BCWs. The chemical oxygen demand (COD) removal efficiencies after 120 min reaction were 64&ndash 74%. The overall apparent reaction rate constants were 0.0101&ndash 0.0117 min&minus 1, which has no obvious relationship with the initial COD of BCW and pre-treatment biological process. The IR demonstrated the highest efficiency due to the enhancement of mass transfer and the utilization efficiency of ozone. Bypass internal circulation can further improve the reactor efficiency. The optimal results were obtained with the ozone absorption section accounting for 19% of the valid water depth in the reactor and 250% of circulation flow ratio. The long-term and full-scale application of the novel reactor in a continuous mode indicated stable removal of COD and polycyclic aromatic hydrocarbons (PAHs). The results showed that the system of IR is a promising reactor type for tertiary treatment of coking wastewater by catalytic ozonation. |
| Databáze: | OpenAIRE |
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